#!/usr/bin/env python3
# -*- coding: utf-8 -*-

__author__ = 'Michael Liao'

import asyncio, logging

import aiomysql

def log(sql, args=()):
    logging.info('SQL: %s' % sql)   # 生成 日志信息

async def create_pool(loop, **kw):
    logging.info('create database connection pool...')
    global __pool
    __pool = await aiomysql.create_pool(
        host = kw.get('host', 'localhost'),
        port = kw.get('port', 3305),
        user = kw['user'],
        password = kw['password'],
        db = kw['db'],
        charset = kw.get('charset', 'utf8'),
        autocommit = kw.get('autocommit', True),
        maxsize = kw.get('maxsize', 10),
        minsize = kw.get('minsize', 1),
        loop = loop
    )

async def select(sql, args, size=None):
    log(sql, args)
    global __pool
    async with __pool.get() as conn:
        async with conn.cursor(aiomysql.DictCursor) as cur:
            await cur.execute(sql.replace('?', '%s'), args or ())
            if size:
                rs = await cur.fetchmany(size)
            else:
                rs = await cur.fetchall()
        await cur.close()
        logging.info('rows returned: %s' % len(rs))
        # conn.close()
        return rs

async def execute(sql, args, autocommit=True):
    log(sql)
    async with __pool.get() as conn:
        if not autocommit:
            await conn.begin()
        try:
            async with conn.cursor(aiomysql.DictCursor) as cur:
                await cur.execute(sql.replace('?', '%s'), args)
                affected = cur.rowcount
            if not autocommit:
                await conn.commit()
        except BaseException as e:
            if not autocommit:
                await conn.rollback()
            raise
        finally:
            conn.close()   
        return affected

def create_args_string(num):
    L = []
    for n in range(num):
        L.append('?')
    return ', '.join(L)

class Field(object):
    def __init__(self, name, column_type, primary_key, default):
        self.name = name
        self.column_type = column_type
        self.primary_key = primary_key
        self.default = default
    def __str__(self):
        return '<%s, %s:%s>' % (self.__class__.__name__, self.column_type, self.name)

class StringField(Field):

    def __init__(self, name=None, primary_key=False, default=None, ddl='varchar(100)'):
        super().__init__(name, ddl, primary_key, default)

class BoolearnField(Field):

    def __init__(self, name=None, default=False):
        super().__init__(name, 'boolean', False, default)

class IntegerField(Field):
    # def __init__(self, name=None, primary_key=False, default=0,ddl='bigint'):
    def __init__(self, name=None, primary_key=False, default=0):
        super().__init__(name, 'bigint', primary_key, default)

class FloatField(Field):

    def __init__(self, name=None, primary_key=False, default=0.0):
        super().__init__(name, 'real', primary_key, default)

class TextField(Field):

    def __init__(self, name=None, default=None):
        super().__init__(name, 'text', False, default)

class ModelMetaclass(type):

    def __new__(cls, name, bases, attrs):
        if name=='Model':
            return type.__new__(cls, name, bases, attrs)
        tableName = attrs.get('__table__', None) or name
        logging.info('found model: %s (table: %s)' % (name, tableName))
        mappings = dict()
        fields = []
        primaryKey = None
        for k, v in attrs.items():
            if isinstance(v, Field):
                logging.info('  found mapping: %s ==> %s' % (k, v))
                mappings[k] = v
                if v.primary_key:
                    # 找到主键:
                    if primaryKey:
                        raise StandardError('Duplicate primary key for field: %s' % k)
                    primaryKey = k
                else:
                    fields.append(k)
        if not primaryKey:
            raise StandardError('Primary key not found.')
        for k in mappings.keys():
            attrs.pop(k)
        escaped_fields = list(map(lambda f: '`%s`' % f, fields))
        attrs['__mappings__'] = mappings # 保存属性和列的映射关系
        attrs['__table__'] = tableName
        attrs['__primary_key__'] = primaryKey # 主键属性名
        attrs['__fields__'] = fields # 除主键外的属性名
        attrs['__select__'] = 'select `%s`, %s from `%s`' % (primaryKey, ', '.join(escaped_fields), tableName)
        attrs['__insert__'] = 'insert into `%s` (%s, `%s`) values (%s)' % (tableName, ', '.join(escaped_fields), primaryKey, create_args_string(len(escaped_fields) + 1))
        attrs['__update__'] = 'update `%s` set %s where `%s`=?' % (tableName, ', '.join(map(lambda f: '`%s`=?' % (mappings.get(f).name or f), fields)), primaryKey)
        attrs['__delete__'] = 'delete from `%s` where `%s`=?' % (tableName, primaryKey)
        return type.__new__(cls, name, bases, attrs)

class Model(dict, metaclass=ModelMetaclass):

    def __init__(self, **kw):
        super(Model, self).__init__(**kw)

    def __getattr__(self, key):
        try:
            return self[key]
        except KeyError:
            raise AttributeError(r"'Model' object has no attribute '%s'" % key)

    def __setattr__(self, key, value):
        self[key] = value

    def getValue(self, key):
        return getattr(self, key, None)

    def getValueOrDefault(self, key):
        value = getattr(self, key, None)
        if value is None:
            field = self.__mappings__[key]
            if field.default is not None:
                value = field.default() if callable(field.default) else field.default
                logging.debug('using default value for %s: %s' % (key, str(value)))
                setattr(self, key, value)
        return value

    @classmethod
    async def findAll(cls, where=None, args=None, **kw):
        ' find objects by where clause. '
        sql = [cls.__select__]
        if where:
            sql.append('where')
            sql.append(where)
        if args is None:
            args = []
        orderBy = kw.get('orderBy', None)
        if orderBy:
            sql.append('order by')
            sql.append(orderBy)
        limit = kw.get('limit', None)
        if limit is not None:
            sql.append('limit')
            if isinstance(limit, int):
                sql.append('?')
                args.append(limit)
            elif isinstance(limit, tuple) and len(limit) == 2:
                sql.append('?, ?')
                args.extend(limit)
            else:
                raise ValueError('Invalid limit value: %s' % str(limit))
        rs = await select(' '.join(sql), args)
        return [cls(**r) for r in rs]

    @classmethod
    async def findNumber(cls, selectField, where=None, args=None):
        ' find number by select and where. '
        sql = ['select %s _num_ from `%s`' % (selectField, cls.__table__)]
        if where:
            sql.append('where')
            sql.append(where)
        rs = await select(' '.join(sql), args, 1)
        if len(rs) == 0:
            return None
        return rs[0]['_num_']

    @classmethod
    async def find(cls, pk):
        ' find object by primary key. '
        rs = await select('%s where `%s`=?' % (cls.__select__, cls.__primary_key__), [pk], 1)
        if len(rs) == 0:
            return None
        return cls(**rs[0])

    async def save(self):
        args = list(map(self.getValueOrDefault, self.__fields__))
        args.append(self.getValueOrDefault(self.__primary_key__))
        rows = await execute(self.__insert__, args)
        if rows != 1:
            logging.warn('failed to insert record: affected rows: %s' % rows)

    async def update(self):
        args = list(map(self.getValue, self.__fields__))
        args.append(self.getValue(self.__primary_key__))
        rows = await execute(self.__update__, args)
        if rows != 1:
            logging.warn('failed to update by primary key: affected rows: %s' % rows)

    async def remove(self):
        args = [self.getValue(self.__primary_key__)]
        rows = await execute(self.__delete__, args)
        if rows != 1:
            logging.warn('failed to remove by primary key: affected rows: %s' % rows)













# # !/usr/bin/env/ pyhton3
# # _*_ coding:utf-8 _*_ 

# # __author__ = "Chimu"
# # Time:2016-10-7 
# # 创建一个ORM(对象关系映射-Object Relation Mapping)
# # ORM 应用于实现面向对象中不同类型系统的数据之间的转换
# # Web框架使用了基于asyncio的aiohttp，这是基于协程的异步模型

# import asyncio, logging

# import aiomysql

# # import logging; logging.basicConfig(level=logging.INFO)
# from logging import log

# # 全局的连接池
# # 连接池由全局变量__pool存储，缺省的情况下将编码设置为utf-8，自动提交事物

# @asyncio.coroutine 
# def create_pool(loop,**kw): 			# 声明原生协程
# 	logging.info('creat database connection pool...')
# 	global __pool
# 	__pool = yield from aiomysql.create_pool(
# 		host = kw.get('host','localhost'),
# 		port = kw.get('port',3305),
# 		user = kw['user'],
# 		password = kw['password'],
# 		db = kw['db'],
# 		charset = kw.get('charset','utf-8'),
# 		autocommit = kw.get('autocommit',True),
# 		maxsize = kw.get('maxsize',10),
# 		minsize = kw.get('minsize',1),
# 		loop = loop
# 	)

# @asyncio.coroutine
# def destory_pool():
#     global __pool
#     if __pool is not None :
#         __pool.close()
#         yield from __pool.wait_closed()

# # SELECT语句，用函数select执行，需要传入的SQL语句和SQL参数
# @asyncio.coroutine
# def select(sql, args=None, size=None):
#     print('select : ', sql, args)
#     global __pool
#     with (yield from __pool) as conn:
#         cur = yield from conn.cursor(aiomysql.DictCursor)
#         yield from cur.execute(sql.replace('?', '%s'), args or ())
#         if size:
#             rs = yield from cur.fetchmany(size)
#         else:
#             rs = yield from cur.fetchall()
#         yield from cur.close()
#         logging.info('rows returned: %s' % len(rs))
#         conn.close()
#         return rs

# # 执行INMSERT,UPDATE,DELETE语句，可以定义一个通用的execute()函数，
# # 这三种SQL的执行都需要相同的参数，以及返回一个整数表示影响的行数：
# # execute()函数和select()函数所不同的是，cursor对象不返回结果集，而是通过rowcount返回结果数。
# @asyncio.coroutine
# def execute(sql, args):
#     print('execute : ', sql, args)
#     global __pool
#     # log(sql)
#     with (yield from __pool) as conn:
#         try:
#             cur = yield from conn.cursor()
#             yield from cur.execute(sql.replace('?', '%s'), args)
#             affected = cur.rowcount
#             yield from cur.close()
#         except BaseException as e:
#             raise RuntimeError(r"MYSQL have same date %s" % args)
#         conn.close()
#         return affected
#         # finally:
#             # conn.close()   # 测试，执行完sql语句后，进行释放与数据库的连接
#         # return affected

# def create_args_string(num):
# 	L=[]
# 	for n in range(num):
# 		L.append('?')
# 		return ','.join(L)

# class Field(object):

# 		def __init__(self,name,column_type,primary_key,default):
# 			self.name = name
# 			self.column_type =column_type
# 			self.primary_key = primary_key
# 			self.default = default

# 		def __str__(self):
# 			return '<%s,%s:%s>' % (self.__class__.__name__,self.column_type,self.name)

# class StringField(Field):

# 	def __init__(self, name=None,primary_key=False,default=None,dd1='varhcar(100)'):
# 		super().__init__(name,dd1,primary_key,default)

# class BoolearnField(Field):

# 	def __init__(self,name=None,default=False):
# 		super().__init__(name,'boolean',False,default)

# class IntegerField(Field):
# 	def __init__(self,name=None, primary_key=False ,default=0):
# 		super().__init__(name,'bigint',primary_key,default)

# class FloatField(Field):

#     def __init__(self, name=None, primary_key=False, default=0.0):
#         super().__init__(name, 'real', primary_key, default)

# class TextField(Field):

#     def __init__(self, name=None, default=None):
#         super().__init__(name, 'text', False, default)

# class ModelMetaclass(type):

#     def __new__(cls, name, bases, attrs):
#          #排除Model类本身
#         if name=='Model':
#             return type.__new__(cls, name, bases, attrs)

#         #获取表的名字    
#         tableName = attrs.get('__table__', None) or name
#         logging.info('found model: %s (table: %s)' % (name, tableName))

#         #获取所有Filed和主键名
#         mappings = dict()
#         fields = []
#         primaryKey = None
#         #遍历类的所有属性，把数据库表单 另外存储
#         for k, v in attrs.items():
#             if isinstance(v, Field):
#                 logging.info('  found mapping: %s ==> %s' % (k, v))
#                 mappings[k] = v     #存入mappings中
#                 if v.primary_key:   #这个数据是主键
#                     # 找到主键:
#                     if primaryKey:  #判断是否为单一主键, 不是就抛异常
#                         raise StandardError('Duplicate primary key for field: %s' % k)
#                     primaryKey = k
#                 else:
#                     fields.append(k)    #除主键以外的属性名
#         if not primaryKey:  #没有主键抛异常
#             raise StandardError('Primary key not found.')

#         #把数据库类别从属性中抛掉
#         for k in mappings.keys():
#             attrs.pop(k)
#         escaped_fields = list(map(lambda f: '`%s`' % f, fields))
#         attrs['__mappings__'] = mappings # 保存属性和列的映射关系
#         attrs['__table__'] = tableName
#         attrs['__primary_key__'] = primaryKey # 主键属性名
#         attrs['__fields__'] = fields # 除主键外的属性名
#         attrs['__select__'] = 'select `%s`, %s from `%s`' % (primaryKey, ', '.join(escaped_fields), tableName)
#         attrs['__insert__'] = 'insert into `%s` (%s, `%s`) values (%s)' % (tableName, ', '.join(escaped_fields), primaryKey, create_args_string(len(escaped_fields) + 1))
#         attrs['__update__'] = 'update `%s` set %s where `%s`=?' % (tableName, ', '.join(map(lambda f: '`%s`=?' % (mappings.get(f).name or f), fields)), primaryKey)
#         attrs['__delete__'] = 'delete from `%s` where `%s`=?' % (tableName, primaryKey)
#         return type.__new__(cls, name, bases, attrs)

# class Model(dict, metaclass=ModelMetaclass):

#     def __init__(self, **kw):
#         super(Model, self).__init__(**kw)

#     def __getattr__(self, key):
#         try:
#             return self[key]
#         except KeyError:
#             raise AttributeError(r"'Model' object has no attribute '%s'" % key)

#     def __setattr__(self, key, value):
#         self[key] = value

#     def getValue(self, key):
#         return getattr(self, key, None)

#     def getValueOrDefault(self, key):
#         value = getattr(self, key, None)
#         if value is None:
#             field = self.__mappings__[key]
#             if field.default is not None:
#                 value = field.default() if callable(field.default) else field.default
#                 logging.debug('using default value for %s: %s' % (key, str(value)))
#                 setattr(self, key, value)
#         return value

#     @classmethod
#     @asyncio.coroutine
#     def findAll(cls, where=None, args=None, **kw):
#         ' find objects by where clause. '
#         sql = [cls.__select__]
#         if where:
#             sql.append('where')
#             sql.append(where)
#         if args is None:
#             args = []
#         orderBy = kw.get('orderBy', None)
#         if orderBy:
#             sql.append('order by')
#             sql.append(orderBy)
#         limit = kw.get('limit', None)
#         if limit is not None:
#             sql.append('limit')
#             if isinstance(limit, int):
#                 sql.append('?')
#                 args.append(limit)
#             elif isinstance(limit, tuple) and len(limit) == 2:
#                 sql.append('?, ?')
#                 args.extend(limit)
#             else:
#                 raise ValueError('Invalid limit value: %s' % str(limit))
#         rs = yield from select(' '.join(sql), args)
#         return [cls(**r) for r in rs]

#     @classmethod
#     @asyncio.coroutine
#     def findNumber(cls, selectField, where=None, args=None):
#         ' find number by select and where. '
#         sql = ['select %s _num_ from `%s`' % (selectField, cls.__table__)]
#         if where:
#             sql.append('where')
#             sql.append(where)
#         rs = yield from select(' '.join(sql), args, 1)
#         if len(rs) == 0:
#             return None
#         return rs[0]['_num_']

#     @classmethod
#     @asyncio.coroutine
#     def find(cls, pk):
#         ' find object by primary key. '
#         rs = yield from select('%s where `%s`=?' % (cls.__select__, cls.__primary_key__), [pk], 1)
#         if len(rs) == 0:
#             return None
#         return cls(**rs[0])

#     @asyncio.coroutine
#     def save(self):
#         args = list(map(self.getValueOrDefault, self.__fields__))
#         args.append(self.getValueOrDefault(self.__primary_key__))
#         rows = yield from execute(self.__insert__, args)
#         if rows != 1:
#             logging.warn('failed to insert record: affected rows: %s' % rows)

#     @asyncio.coroutine
#     def update(self):
#         args = list(map(self.getValue, self.__fields__))
#         args.append(self.getValue(self.__primary_key__))
#         rows = yield from execute(self.__update__, args)
#         if rows != 1:
#             logging.warn('failed to update by primary key: affected rows: %s' % rows)

#     @asyncio.coroutine
#     def remove(self):
#         args = [self.getValue(self.__primary_key__)]
#         rows = yield from execute(self.__delete__, args)
#         if rows != 1:
#             logging.warn('failed to remove by primary key: affected rows: %s' % rows)